How do I solve Optional Boss in Yukiko's castle?

I was wondering if I would be able to beat this boss at my leisure or if I would have to do it before the next bit of story progression. I guess this question applies to any optional boss in the game.6 years ago

Just use Tarunda to lower the boss attacks. Your party level should be around 20 for easy win because his Rampage skill can kill your party in single turn. I recommend using a Persona that strong in physical affinity to prevent your MC death(Game Over). After victory, you will gain Yukiko's weapon which increase her SP 50 point.6 years ago 10

For this boss, it is gonna be HELL if you're underleveled since rampage OHKO's your entire party. Trust me, I experienced it personally. Best way is to level up a bit in Kanji's dungeon and then go back to own the optional boss6 years ago 01

Eh, I beat him with MC at 17 and others at 15-16. I just lowered his defense, use full assault order (whatever that attack increasing item), and start pounding him before he uses rampage.

I get my MC to use rakunda and bufu, Yosuke use Sonic punch, Chie use Bufu, Yukiko for healing. I win in 6-7 turns barring any crits and/or rampages (got lucky once, only Yukiko died and the others dodged).

Granted, I actually needed to restart a few times before winning.6 years ago 10

Get two of Eagle Eye accesories that gives you evade phys. You can found it inside rare chest in the castle. Get slime to level 7 to learn resist phys, then create any spellcaster type persona by using the slime as an ingredients, to make it inherit resist phys.